   (inode-find [inode shift hash key]
     (let [idx  (mask hash shift)
           node (aget arr idx)]
-      (if (coercive-not= nil node)
+      (if-not (nil? node)
         (.inode-find node (+ shift 5) hash key)
         nil)))
 
   (inode-find [inode shift hash key not-found]
     (let [idx  (mask hash shift)
           node (aget arr idx)]
-      (if (coercive-not= nil node)
+      (if-not (nil? node)
         (.inode-find node (+ shift 5) hash key not-found)
         not-found)))
 

                  (if (zero? (bit-and (bit-shift-right-zero-fill bitmap i) 1))
                    (recur (inc i) j)
                    (do (aset nodes i
                              (if (coercive-not= nil (aget arr j))
                                (.inode-assoc! cljs.core.BitmapIndexedNode/EMPTY
                                               edit (+ shift 5) (cljs.core/hash (aget arr j)) (aget arr j) (aget arr (inc j)) added-leaf?)
                                (aget arr (inc j))))

  empty, returns nil.  (seq nil) returns nil. seq also works on
  Strings."
  [coll]
  (if-not (nil? coll)
    (if (satisfies? ASeq coll)
      coll
      (-seq coll))))
